Growing Mango Trees from Seeds, Days 249-573

I transplanted this mango plant from a tube containing a 50% sand/50% clay soil mixture into a homemade planter containing a 75% sand/25% clay soil mixture on 2019/12/1. I cut away the bottom 70% of the taproot that day. It took this plant TEN MONTHS to recover from that transplant, but I think ultimately what mattered was the latest transplant into a 90+% sand/10% clay soil mixture on 2020/8/2, 8 months after the previous transplant. Although I haven't dug into the sand to see the room system in the last 3 months, I know that root development restarted and must be quite robust, as I saw new lateral roots growing from the beginning of the taproot right under the base of the stem when the sand got washed away from water recently.
This balcony started receiving directly sunlight around the end of August, but the leaves on this mango plant didn't start receiving direct sunlight until late September. Perhaps the sunlight helped resurrect my mango plant. The fertilizer seemed to breathe new life into the shoot apical meristem, but it wasn't enough in full shade conditions. The sugar water definitely did nothing observable even after dunking the leaves in a 1 tablespoon per Liter solution for 48 hours, but I did learn that it doesn't cause leaf burn.
And finally, there's no point in continuing to call this series "Growing a Mango Seedling in a Tube" anymore. Since this series is my first long term successful mango series, it will take over the mantle of the 2016 "Growing Mango Trees from Seeds" series.